反应详情

温度

45 °C

Silica phosphonate chromium (III) resin (48.9 g, PhosphonicS, Ltd.) was placed in a 5 L round bottom flask equipped with a condenser, thermowell, overhead stirrer, and sparge tube. Two (2) L of t-butanol and valencene distillate (68%, 500 g, 1.67 moles, 1 eq) were added, the contents were heated to 45° C., and the heterogeneous suspension was allowed to stir as oxygen was sparged through the solution (ca 1.5 L/min) and nitrogen flushed over the head-space. 70% t-butyl hydroperoxide in water (TBHP, 315 g, 2.45 moles, 1.47 eq) was added to the solution over 2 hrs while the temperature of the reaction was heated and maintained at 60±5° C. The reaction was allowed to stir until >90% of the valencene was consumed, as determined by gas chromatography. The reaction was then allowed to cool to room temperature and the silica catalyst removed by filtration. The flask and resin were washed with 500 mL isopropanol. One (1) L of deionized water was added to the combined organic solution (t-butanol and isopropanol), and the mixture was concentrated under reduced pressure by evaporation to afford an amber colored oil. The oil was dissolved in 3 L of toluene and washed with 3.125 L of 15% sulfuric acid for 15 minutes with vigorous agitation. The aqueous layer was removed and re-extracted with 1 L of toluene. The combined toluene layers were then washed three times with 2.5 L of 1 M sodium hydroxide, twice with 500 mL saturated sodium chloride, and dried over anhydrous magnesium sulfate. After filtration, the solvent was removed under reduced pressure by evaporation to afford 378 g of viscous amber oil (33% nootkatone by weight, 0.57 moles, 34% yield).

1. customSilica phosphonate chromium (III) resin (48.9 g, PhosphonicS, Ltd.) was placed in a 5 L round bottom flask
2. customequipped with a condenser
3. customthermowell, overhead stirrer, and sparge tube
4. customwas sparged through the solution (ca 1.5 L/min) and nitrogen
5. customflushed over the head-space
6. temperaturewas heated
7. temperaturemaintained at 60±5° C
8. customwas consumed
9. temperatureto cool to room temperature
10. customthe silica catalyst removed by filtration
11. washThe flask and resin were washed with 500 mL isopropanol
12. additionOne (1) L of deionized water was added to the combined organic solution (t-butanol and isopropanol)
13. concentrationthe mixture was concentrated under reduced pressure by evaporation
14. customto afford an amber colored oil
15. washwashed with 3.125 L of 15% sulfuric acid for 15 minutes with vigorous agitation
16. customThe aqueous layer was removed
17. extractionre-extracted with 1 L of toluene
18. washThe combined toluene layers were then washed three times with 2.5 L of 1 M sodium hydroxide
19. dry with materialtwice with 500 mL saturated sodium chloride, and dried over anhydrous magnesium sulfate
20. filtrationAfter filtration
21. customthe solvent was removed under reduced pressure by evaporation